10个人依次抽签，10张签中有2张幸运签，则第3人抽到幸运签的概率为____。（保留三位有效数字）

PPS抽样是概率与规模成比例抽样，即赋予规模不等的群体与其规模成比例的入样概率，使每个调查对象都有被抽中的同等概率。（）

40.ThenamesofWrightbrotherswerefirmlyandforeverlinkedinthehistoryof____________.

40.Itsmainaimwastoraiseconsumers’______________ofenvironmentalissues.

40.Theirnumbershaveonlydroppedby______________fivepercent.

40.ThenamesofWrightbrotherswerefirmlyandforeverlinkedinthehistoryof____________.

40.以下对白血病患者进行护理时,错误的是（）

40儿童缺铁性贫血的主要原因是（）

40.“Don'tforgettomentionme”中，mention可以替换成（）。

40.ThefirstEnglishpermanentsettlementwasfoundedinCalifornia.

某企业的预计的资本结构中，资产负债率比率为40%，债务税前资本成本为12%。目前市场上的无风险报酬率为8%，市场上所有股票的平均收益率为16%，公司股票的β系数为1.2，所得税税率为25%，则加权平均资本成本为（　）%。　

某企业某年度年末流动负债为50万元，年初存货为40万元，全年主营业务成本为80万元，年末流动比率为2.5，速动比率为1.3，则本年度存货周转次数为（）次。

Theproblemwithaparentalopen-walletpolicy,saysGodfrey:“ifyou’realwaysgivenmoney,whywouldithaveanyvaluetoyou?”Earnedmoneyisspentmorewisely,shesays.“You’reteachingthemthatthereisnotanentitlementprograminlife.Thewayyougetitisyouearnit.”Godfreythinksanallowanceshouldbechore-based,andshedividesworkintotwocategories:citizen-of-the-householdchoresandwork-for-paychores.“Thepunishmentfornotdoingyourwork-for-paychoresisyoudon’tgetpaid.”Otherexperts,includingJaynePearl,authorofKidsandMoney,believethateveryfamilymemberisentitledtoasmallpieceofthefinancialpieandthatitshouldn’tbetiedtowork.Doingso“complicatesthingsunnecessarilyandimbuesallowancewithpowerstrugglesandcontrolissues,”saysPearl.“Ithinkof(anallowance)aslearningcapital....Theyhavetohavesomemoneytopracticewith.”40.WhichofthefollowingwouldGodfreyprobablyagree?___________

Theproblemwithaparentalopen-walletpolicy,saysGodfrey:“ifyou’realwaysgivenmoney,whywouldithaveanyvaluetoyou?”Earnedmoneyisspentmorewisely,shesays.“You’reteachingthemthatthereisnotanentitlementprograminlife.Thewayyougetitisyouearnit.”Godfreythinksanallowanceshouldbechore-based,andshedividesworkintotwocategories:citizen-of-the-householdchoresandwork-for-paychores.“Thepunishmentfornotdoingyourwork-for-paychoresisyoudon’tgetpaid.”Otherexperts,includingJaynePearl,authorofKidsandMoney,believethateveryfamilymemberisentitledtoasmallpieceofthefinancialpieandthatitshouldn’tbetiedtowork.Doingso“complicatesthingsunnecessarilyandimbuesallowancewithpowerstrugglesandcontrolissues,”saysPearl.“Ithinkof(anallowance)aslearningcapital....Theyhavetohavesomemoneytopracticewith.”40.WhichofthefollowingwouldGodfreyprobablyagree?___________

建立数据库表时，将年龄字段值限制在12～40岁之间的这种约束属于实体完整性约束